Rotary pump



L. 5. SMITH ROTARY PUMP Aug. 7, 1945.

Filed Oct. 4, 1943 3nnentor: LLOYD S. SMITH, ew $2? Patented 'Aug. 7, 1945 UNITED STATES PATENT orrlcs ROTARY PUMP Lloyd S. Smith, Tustin, Calif.

Application October 4, 1943, Serial No. 504,892

3 Claims. (Cl. 23079) This invention has to do with improvements in rotary pumps, compressors and the like, in which the rotor is contained within a non-circular (e. g., elliptical) chamber containing as the direct fluid displacement medium, a body of liquid, such as mercury, surrounding and rotating with the rotor. The latter carries a cirwhich the mercury is displaced radially by reason of the differential in the shape characteristics of the rotor and the chamber within which it revolves, to alternately enlarge and reduce the volumes of the rotor-carried displacement chambers, and thereby create the pumping effect.

The invention is particularly concerned with rotary pumps of this type in which .the rotor revolves about a hub containing fluid inlet and invention in certain typical and preferred forms.

* In the drawing:

. cular series of vanes forming chambers within outlet ports or passages from and into which the fluid being pumped or compressed flows at the bottom or radially inner portions of the rotor-carried displacement chambers. In this manner, the intake of fluid to the rotor and the discharge of fluid therefrom, are controlled in accordance with the relative positions of the rotor and its stationary hub.

One major object of the invention is to employ a rotor of such open formation with respect to the communications between the displacement chambers and the intake and outlet ports in the hub as to assure high volumetric efliciency and, where desired, the capacity of the apparatus for efficient pumping of liquids. In furtherance of this object, the displacement chambers are given open communication with the hub-contained ports across substantially the entire areas of the inner-most portions of the displacement chambers, and the hub ports are given such formation as to have open and unrestricted communication with the registering rotor chambers. As will appear, where the pump is to be used as a gas compressor, the outlet ports in the hub may be designed to communicate with the displacement chambers only after compression of the gas therein to the desired pressure.

Another important feature and object of the invention is to provide an extremely simple and practical rotor and hub construction particularly adaptable for adjustment to compensate for wear of engaging relatively rotating surfaces, and to permit rotational adjustment of the hub within the rotor case. Such features of adjustment are incorporated in the pump by providing tapered surfaces of engagement between the rotor and hub, and by mounting the hub for turning adjustment at one end of the rotor casing, all as will be explained to better advantage in the following detailed description.

Throughout this description, reference is had to the accompanying drawing illustrative of the Fig. 1 is a longitudinal sectional view of the p mp;

Fig. 2 is a cross-section on line 2-2 of Fig.

Fig. 3 is a sectional view of the hub taken in the aspect of broken line 3-3 of Fig. 1; and

Fig. 4 is a similar view illustrating a modification of the hub-contained discharge'ports adapting the pump for use as a gas compressor.

The pump may be described generally as comprising a case Ill containing a rotor lldriven by a shaft l2 which may have any desired bear- ,ing support (not shown) beyond or independently of the pump proper. The case I ll comprises an intermediate section l3 having suitable base supports I4 and forming a non-circular and preferably substantally elliptical chamber l5. This chamber contains a body of mercury IE or any other suitable liquid, depending upon the nature and properties of the fluid being pumped, which in combination with the rotor constitutes the pumping or fiulddisplacement medium. At opposite sides of the intermediate section l3 of the case is a pair of rings l1 and I8 having circular bores IS, the diameter of which may be substantially equal to the short diameter of the elliptical chamber i5. One end of the case is closed by a plate 20 and the opposite end by a housing 2i through the end of which the shaft l2 extends and which contains a suitable stufflng box 22 for preventing fluid leakage from the case along the shaft. The described sections of the case may be interconnected in any suitable manner, as by means of bolts 23. e

The rotor ll comprises an outer end portion 24 keyed at 25 to the shaft if within the housing 2i, and having an integral inner portion consisting of a pair of flanges 2G and 21! interconnected by a circular arrangement of equally spaced radial vanes 28. The rotor flanges Z6 and 21 may have runningengagement within the bores IQ of ring sections ll and I8 of the case. The outer ends 29 of .the vanes 28 terminate at substantially the outer or running surfaces of the flanges 26 and TI, and the inner ends 30 of the vanes terminate substantially opposite the adjacent edge of the bore in ring W.

The rotor engages and revolves about a hub 3| extending through a. circular opening it in t e case, into the hollow interior of the rotor. The hub has a cylindric surface 33 continuing into the rotor and engaging the straight or cylindric portions 34 of the rotor bore. Beyond surface 33, the hub has a tapered surface 35 engaging correspondingly tapered portions of the rotor bore. The hub is secured to the casing by screws 36 extending through arcuate slots 31 in flange 38 into the end plate Bil of the case,

suitable spacing means, such as one or more shims 39, being inserted between flange II and the case to accurately position the hub axially within the case. For purposes of clarityand illustration, the hub surfaces at 35 are shown to have a substantial degree of taper, which in the actual construction may be somewhat less.

As best illustrated in Fig. 2, the hub contains a pair of inlet ports or passages 40 and H, and a pair of outlet passages 42 and 43 separated by the intersecting webs 44. It will be observed that in the liquid pump design of Fig. 2, the bottom or radially inner-most portions of the displacement chambers 45 are in direct and open communication with the hub passages, across substantially the entire bottom areas of the chambers. If desired, ports 46 and 41 interconnecting respectively the inlet and outlet passages in the hub, may be provided to balance the pressures therein. Also, if desired, the pressure in the intake passages in and ii may be communicated through passages" into space 49 to oppose any rotor end thrust toward the right.

In considering the operation of the pump, it will be observed, see Fig. 2, that in being bodily rotated with and about the rotor, the mercury It follows the elliptical wall i of the rotor chamber and thus becomes displaced maximum distances away from the rotor at the long axis of the chamber. innermost displacement of the mercury within the rotor occurs at the short axis of the chamber. Thus, assuming the rotor to turn in the direction indicated by the arrow, fluid from the inlet passages 40 and ll enters and fills the chambers 45 to the point of cut-off when the vanes 28 reach the outer edges of the hub webs 44. Thereafter, the fluid is progressively displaced from chambers 45 into the discharge passages 42 and 43. The delivery of fluid to and from the pump may occur by way of any suitable manifold or other connections with the hub-contained passages. As illustrative, I have shown attached to the hub the elbow section 50 of a manifold containing passages 5| registering with and arranged corresponding to the inlet and outlet passages in the hub. Hub 50 forms a trap for any mercury displaced from the rotor chamber through any of the hub passages.

Over a period of operation, wear and the development of clearances may occur at the engaging rotor and hub surfaces 35. To compensate for such wear, screws 36 may be loosened, and the thickness of the shim 39 adjusted to permit axial movement within the rotor to restore the surfaces to proper running engagement. It will be observed that beyond the inner end of the hub, the rotor bore at 52 is straight or cylindric, thus permitting the described adjustment of the hub after any wearing or scoring of the surfaces at an initially set position. The engagement of the rotor and hub along the cylindric surface 34 assures the maintenance of size relationship, and normally an effective seal between the rotor and hub, independently of whatever variances may exist in the engagement or relationship of the rotor and hub along the tapered surfaces 35.

If for any reason it is desired to vary the angular position of the hub, and particularly the vanes 44, within the case, rotational adjustment of the hub may be effected by loosening screws 36 and turning the hub within the limits of slots 31, which, of course, may be arcuately extended to whatever limits necessary.

Fig. 4 illustrates a modification of the invention in which the ports of fluid entry from the displacement chambers 45 into the discharge passages 42 and 43, have been reduced in size circularly of the rotor, to effect compression of an elastic fluid where the pump is'to be used as a gas compressor. As her'e illustrated, the hub webs carry a pair of flanges 53 extending in the direction of rotation of the rotor such distances as may be desired beyond the point of cut-oi! at the webs from communication with the inlet ports. The inner ends of the chambers ll thus are sealed along extents causing the gas to become compressed before release through ports ll into the outlet passages 42 and 43, to a degree determined by the arcuate extent of the flanges I3.

I claim:

1. Apparatus of the character described comprising a case containing a chamber, a rotor within said chamber and having peripheral portions spaced from the wall thereof, circularly spaced vanes on the rotor, a body of liquid surrounding and displaced by the rotor radially within said chamber to create within displacement chambers between said vanes spaces of varying volume, a stationary hub extending through an end wall of the case and 'having a tapered surface engaging a tapered bore within the rotor and having adjacent said tapered surface a cylindrical surface within a. cylindrical bore in the rotor, inlet and outlet passages in said hub communicable with said displacement chambers, and a mounting for the hub on the case permitting axial and rotational adjustment of the hub relative to the rotor.

2. Apparatus of the character described comprising a case containing a chamber, a rotor within said chamber and having peripheral portions spaced from the wall thereof, circularly spaced vanes on the rotor, a body of liquid surrounding and displaced by the rotor radial y within said chamber to create within displacement chambers between said vanes spaces of varying volume, a stationary hub extending through an end wall of the case and having tapered surfaces engaging tapered bores within the rotor at opposite sides of said displacement chambers, said hub having adjacent said tapered surface a cylindrical surface within cylindrical bores in the rotor and case, inlet and outlet passages in said hub communicable with said displacement chambers, and a mounting for the hub on the case permitting axial adjustment of the hub relative to the rotor.

3. Apparatus of the character described comprising a case containing a chamber, a rotor within said chamber and having peripheral portions spaced from the wall thereof, circularly spaced vanes on the rotor, a body of liquid surrounding and displaced by the rotor radially within said chamber to create within displacement chambers between said vanes spaces of varying volume, a stationary hub having a cylindric surface extending through corresponding bores in the end wall of the case and within the rotor at one side of said displacement chamber, said hub having tapered surfaces engaging tapered surfaces within the rotor at opposite sides of said displacement chambers, inlet and outlet passages in said hub communicable with said displacement chambers, and means for adjusting the hub axially relative to the rotor.

LLOYD B. SMITH. 

